Washington: The importance of sunscreen cannot be undermined but there are concerns that it might hamper the production of vitamin D in the body. However, a recent study found an increase of vitamin D in participants during a week of cloudless weather, with very high ultraviolet (UV) index, even when sunscreens were used properly and prevented sunburn.

The study was published in the British Journal of Dermatology. Sunlight contains UVA (ultraviolet-A) and UVB (ultraviolet-B) radiation, and the latter is essential for vitamin D synthesis. The study compared two sunscreens with the same SPF. Sunscreen with a high UVA protection factor enabled significantly higher vitamin D synthesis than a low UVA protection factor sunscreen, likely because it allows more UVB transmission.

The findings indicate that the benefits of sunscreen use can be obtained without compromising vitamin D levels. "Sunlight is the main source of vitamin D. Sunscreens can prevent sunburn and skin cancer, but there has been a lot of uncertainty about the effects of sunscreens on vitamin D," said lead author Antony Young, King's College London.

"Our study, during a week of perfect weather in Tenerife, showed that sunscreens, even when used optimally to prevent sunburn, allowed excellent vitamin D synthesis," Young said.